PROGNOSTIC FACTORS OF MALIGNANT MESOTHELIOMA OF THE PLEURA

Background. Pleural mesothelioma is a rare condition with a poor prognosis. The area of Monfalcone, North East Italy, provided a unique opportunity to study the disease because of its past heavy exposure to asbestos in local harbors and shipyards and its high necropsy rates. Methods. The effects of various patient and tumor characteristics on survival were evaluated in 80 patients (73 males and 7 females; median age, 69) of histologically or cytologically confirmed malignant mesothelioma of the pleura. These patients were examined between October 1979 and October 1991 at the General Hospital of Monfalcone in the Friuli-Venezia Giulia region. Substantial exposures to asbestos were identified in 79 patients. Results. Median survival rate was 13 months (range, 2-44 months), and overall 2- and 5-year survival rates were 23% and 0%, respectively. The factors that exerted a significant favorable influence on survival were as follows: (1) age younger than 65; (2) performance status less than or equal to one; (3) lack of less than or equal to 10% weight loss at any time; (4) Stages I and II; (5) epithelial or mixed histologic type; and (6) presence of pleural fluid with mesothelial cells but without neoplastic cells. When these factors were introduced in a Cox proportional hazard model, age, stage, and histologic type were the only independent prognostic factors. The increased hazards for patients, ages 65-74 (as compared to < 65), and for patients with sarcomatous histologic type (as compared to epithelial type) were 2.6 (95% confidence interval [CI], 1.2-5.7) and 4.5 (95% CI, 1.6-12.8). Conclusions. Survival rate in 24 untreated patients (median, 10 months) and 56 patients variously treated (median, 15 months) did not differ significantly. The availability of large portions of tumor specimens for histologic examinations in 77 of 80 patients, chiefly from high necropsy rate, strengthens the value of the present analysis of prognostic factors.